1. Field of the Invention
The present invention relates to a face image recording system applied to doorway monitoring in a facility to record a user's face image as log data.
2. Description of the Related Art
In conventional doorway monitoring for a specific room, it is necessary to check whether a person who wants to enter or leave the room is permitted to do so. For example, a doorway monitoring system for managing entrance/leaving with respect to a specific room identifies a person by various identification methods, thereby checking whether the person is permitted to enter or leave the room. Also, in electronic commerce it is necessary to check whether a person who has accessed has a legal qualification. For example, an information management system used in electronic commerce confirms a person by identifying him or her by various identification methods.
For this reason, a doorway monitoring system or an information management system is desired to be able to mechanically (automatically) identify a person with no or minimum intervention of a third party.
The conventional person identification methods are roughly classified into the following three methods.
(1) Person Identification Method Using Person's Belongings
A person identification method using person's belongings is to identify a person by his or her identification card such as a passport or license. This person identification method using person's belongings also includes a method of identifying a person by using a storage medium such as a magnetic card, wireless card, or IC card. In a broad sense, the door keys of an entrance and a safe, and the ignition key of a car are also included in the person identification method using person's belongings.
(2) Person Identification Method Using Stored Information (PIN; Personal Identification Number)
For example, a person identification method using information such as a password belongs to this person identification method using stored information. This person identification method using stored information is often combined with the person identification method using person's belongings. As an example, a financial agency such as a bank identifies a user by combining a credit card with a password of four figures stored by the user.
(3) Person Identification Method Using Biomedical Features
A representative example of this person identification method using biomedical features is fingerprint collation. A person can also be identified by using biomedical features (biometrics) such as a retina, iris, palm shape, voiceprint, signature (handwriting), and face. Person identification methods using a fingerprint, voiceprint, and signature have been conventionally used in crime investigation. These person identification methods using biomedical features identify a person by collation with sample data. Also, these person identification methods using biomedical features are not always mechanically performed. For example, in a person identification method using a credit card, a person is identified by visually collating a signature on the card with a signature written by the person. That is, the person identification method using biomedical features is often combined with (1) the person identification method using person's belongings and (2) the person identification method using stored information.
Unfortunately, the conventional person identification methods described above are imperfect since they have the following problems.
The drawback of (1) the person identification method using person's belongings is that a belonging for identifying a person can be lost, stolen, or forged. The drawback of (2) the person identification method using stored information is that a person may forget stored information such as a password, or stored information may be estimated or randomly attacked by another person. The drawback of (3) the person identification method using biomedical features is that influences such as changes in biomedical features over time are unavoidable, so collation errors cannot be completely eliminated.
In addition, in doorway monitoring it is sometimes necessary to save information indicating a person who has entered or left. Also, in electronic commerce it is sometimes necessary to save information indicating that a person has approved. In Japan, for example, impressing a seal indicating the name or the like of a person is customarily performed to indicate his or her approval. In a purpose like this which requires a relatively low security level, a certain security can be maintained by saving information indicating person's approval.
If the conventional person authentication method is applied to such a purpose requiring a relatively low security level, installation of the system increases the cost, or the operability worsens. Accordingly, a system which can reduce the installation cost while maintaining a certain security level and which is user-friendly is demanded.